Real-time cell analysis of human cancer cell lines after chemotherapy with functionalized magnetic nanoparticles

Magnetic drug targeting is a new and innovative approach in cancer treatment. In order to avoid the adverse effects of chemotherapy, the therapeutic agent is linked to superparamagnetic nanoparticles which are injected into a tumour-supporting artery and is focused by an external magnetic field to the tumour region in order to provoke maximum local impact. Analysis of nanoparticles and chemotherapeutic substances in human cancer cell culture is necessary to provide respective information for in vivo applications.

The effect of pure mitoxantrone and mitoxantrone bound to nanoparticles was tested on human cancer cell lines using real-time cell analysis (RTCA) and lactate dehydrogenase (LDH) assays. RTCA was performed by impedance measuring. The impedance is expressed as the cell index (CI), which is a parameter of cell viability.

RTCA showed that mitoxantrone when bound to nanoparticles was more toxic than the drug alone. The CI clearly decreased faster after adding the chemotherapeutic bound to nanoparticles than when adding the pure drug alone. However, in the first experiments, the particles themselves showed no toxicity at therapeutically relevant concentrations. These results were confirmed by LDH assays.

The toxic effects of chemotherapeutic agents (e.g. mitoxantrone) on human cancer cell lines (e.g. MCF-7) can be enhanced if these drugs are bound to magnetic nanoparticles. These preliminary data show a dependency on the different application modes of RTCA. The results presented here are a first step for a better understanding of the effectiveness of magnetic drug targeting as a new and innovative cancer treatment.